1. Field of the Invention
This invention relates generally to a system wherein information is transferred between a communications controller and a number of work stations, each of which may include a keyboard and a cathode ray tube display; and more particularly to apparatus for generating high speed signals for transfer of information over a single conductor coaxial bus.
2. Description of the Prior Art
Many data processing systems include a number of work stations. A work station may include a keyboard which permits an operator entry into the system and a cathode ray tube display which displays the information keyed in by the operator for verification before transferring the information to a central processing unit or display information received from the central processing unit.
U.S. Pat. No. 3,500,335 entitled "Random Access--Data Editing Communication Network" describes a data processing system wherein a number of work stations are coupled by a multiconductor cable to a display controller which is in turn coupled to a processor through a phone line.
U.S. Pat. No. 4,017,838 entitled "Data Entry and Recording System Having Field Correct Capability" describes a number of work stations coupled by a multiconductor cable to a multiplexer which is in turn coupled to a central processor unit.
Related U.S. Application Ser. No. 364,381 filed Apr. 1, 1982, describes a system which includes, but does not disclose or claim, the apparatus of the instant invention. The system describes the coupling of displays to device controllers by means of multiconductor cables.
All of the above systems require the use of a multiconductor cable which is costly and also limits the distance the work stations may be from the controller. Also, in past designs the relatively high cost of logic components dictated a design wherein functions were time-shared in a central controller rather than duplicated in each work station.